Ali began her career as a research assistant to Michael Young, working on a project which paved the way for the establishment of Tower Hamlets Summer University, offering independent learning programmes for young people aged 11–25. She helped to develop "Language Line", a national telephone interpreting service in over 100 languages. Between 1997–1999 she was parliamentary assistant to Oona King, MP for Bethnal Green and Bow.[3]

Ali worked on human rights issues at the Foreign Office from 2000–2001. Prior to this, she was a research fellow at the Institute of Public Policy Research (IPPR) focussing on anti-discrimination issues from 1999–2002. From 2002–2005, she worked in the community cohesion unit at the Communities Directorate of the Home Office, leading a work programme to mobilise local and national agencies in the aftermath of the 2001 riots in Burnley, Bradford and Oldham, to prevent further conflict and unrest, challenging central Government to provide appropriate support to these areas.[4]

In October 2013, Ali was appointed Shadow Minister for Education.[19] On 26 September 2014, she resigned from the Labour frontbench Education team to abstain on the Coalition government's House of Commons motion permitting military action against Islamic State of Iraq and the Levant in Iraq.[20] In a letter to the leader of the party Ed Miliband, she wrote "I appreciate the sincerity of members of parliament from all sides of the House who today support military action against ISIL. I know that British Muslims stand united in the total condemnation of the murders that ISIL have committed. However, there is a genuine belief in Muslim and non-Muslim communities that military action will only create further bloodshed and further pain for the people of Iraq," Ali also told Miliband that she remained totally committed to his leadership and was looking forward to his becoming the prime minister in next eight months' time. In his return letter to Ali, Miliband praised her as 'someone with great ability and talent'. Regretting her departure from the frontbench team, the Labour leader added that he accepted the resignation with due respect to her decision.[21][22]